In five studies we demonstrate that task-irrelevant somatic activity influences intertemporal decision making: Arm movements associated with approach (arm flexion), rather than avoidance (arm extension), instigate present-biased preferences. We show that the preference for immediate over delayed gratification is moderated by the sensitivity of the approach system and, owing to learning principles, restricted to arm positions of the dominant hand. This research extends the effects of somatic activity beyond attitude formation and cognition, and provides empirical evidence for the effect of somatic activity on motivational systems.